I usually sell to a NPC. When I finally get another green item though I'm gonna flog it for what it's worth. I can get up to 40k on some things...and I've seen people offering to pay 90k-100k for items they can't find.

ON average I can probably get around 15k, 20k max.

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If you're gonna go out farming, go out on your own with henchies, not other players. It may be that bit harder, but at least you get all the items that are dropped.